I was going to get one and I also have an appointment this month with my ophthalmologist. I called to reschedule but to no avail. I mentioned this laser and was told not to do anything with a laser that I would be looking at because of reflection back even as a guide especially since my eyesight has taken a downturn. Shortly, after that I found my seam guide that attaches to my 401. Saved myself some money and kept my sight on hold.